Can you believe it? Proton, the compatibility layer that allows Windows games to run on Steam Deck / Linux PCs didn't actually have a proper logo for over 5 years.
Valve is a very small company of dedicated engineers and developers. Im sure the folks making things work were busy, and the company just needed a marketing person to come in. Did I get the snark level right? XD Jokes aside, neat logo!
I'm pretty sure that's kinda exactly what happened though, I wouldn't be surprised if it was just that no one thought to add a logo because engineers don't care about shit like that (at least a lot of them don't)
It'll be another 400 years before Valve makes the "this title has no icon" text not look like total ass, but finally somebody over there took a whole minute to grab an icon from steamgriddb dot com